CVE-2019-18805

An issue was discovered in net/ipv4/sysctl_net_ipv4.c in the Linux kernel before 5.0.11. There is a net/ipv4/tcp_input.c signed integer overflow in tcp_ack_update_rtt() when userspace writes a very large integer to /proc/sys/net/ipv4/tcp_min_rtt_wlen, leading to a denial of service or possibly unspecified other impact, aka CID-19fad20d15a6.

Published: 2019-11-07 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2019-18805 is rated High Risk (72.6/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 3.43%). EPSS rose +2.86% over the last day, indicating growing attacker interest. High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2019-18805

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.57% 3.43% +2.86%
2 2025-11-21 1.09% 0.57% -0.52%
3 2025-11-18 — 1.09% —

Full EPSS history (16 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2019-18805

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]
7.5 2.0 HIGH
AV:N/AC:L/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 6.4 [email protected]

Weakness enumeration for CVE-2019-18805

OS Trackers for CVE-2019-18805

vendor priority summary link
debian not yet assigned CVE-2019-18805 not yet assigned priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2019-18805
redhat medium — https://access.redhat.com/security/cve/CVE-2019-18805
suse low CVE-2019-18805 severity low: SUSE including 236 source package names (bpftool-4.18.0-193.el8, cluster-md-kmp-default-4.12.14-122.7.1, …), 528 product×package rows across 89 product lines (HPE Helion OpenStack 8, Image SLES12-SP5-Azure-BYOS, … (89 product lines)): Fixed 502, Known Not Affected 26. https://www.suse.com/security/cve/CVE-2019-18805/
ubuntu low CVE-2019-18805 low priority: Ubuntu including 117 source packages (linux, linux-aws, …), 1274 status rows across 14 suites (bionic, disco, eoan, focal, groovy, hirsute, jammy, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 915, not-affected 192, released 150, ignored 17. https://ubuntu.com/security/CVE-2019-18805

Affected software / configurations for CVE-2019-18805

Vendor Product Version Raw CPE
linux linux_kernel >= 4.4, < 4.4.180 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 4.9, < 4.9.172 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 4.14, < 4.14.115 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 4.19, < 4.19.38 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 5.0, < 5.0.11 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel 5.1 cpe:2.3:o:linux:linux_kernel:5.1:rc1:*:*:*:*:*:*
linux linux_kernel 5.1 cpe:2.3:o:linux:linux_kernel:5.1:rc2:*:*:*:*:*:*
linux linux_kernel 5.1 cpe:2.3:o:linux:linux_kernel:5.1:rc3:*:*:*:*:*:*
linux linux_kernel 5.1 cpe:2.3:o:linux:linux_kernel:5.1:rc4:*:*:*:*:*:*
linux linux_kernel 5.1 cpe:2.3:o:linux:linux_kernel:5.1:rc5:*:*:*:*:*:*
linux linux_kernel 5.1 cpe:2.3:o:linux:linux_kernel:5.1:rc6:*:*:*:*:*:*
linux linux_kernel 5.1 cpe:2.3:o:linux:linux_kernel:5.1:rc7:*:*:*:*:*:*
opensuse leap 15.0 cpe:2.3:o:opensuse:leap:15.0:*:*:*:*:*:*:*
opensuse leap 15.1 cpe:2.3:o:opensuse:leap:15.1:*:*:*:*:*:*:*
redhat enterprise_linux 7.0 cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*
netapp active_iq_unified_manager — cpe:2.3:a:netapp:active_iq_unified_manager:-:*:*:*:*:vmware_vsphere:*:*
netapp data_availability_services — cpe:2.3:a:netapp:data_availability_services:-:*:*:*:*:*:*:*
netapp e-series_santricity_os_controller >= 11.0.0, <= 11.60.3 cpe:2.3:a:netapp:e-series_santricity_os_controller:*:*:*:*:*:*:*:*
netapp hci_management_node — cpe:2.3:a:netapp:hci_management_node:-:*:*:*:*:*:*:*
netapp solidfire — cpe:2.3:a:netapp:solidfire:-:*:*:*:*:*:*:*
netapp steelstore_cloud_integrated_storage — cpe:2.3:a:netapp:steelstore_cloud_integrated_storage:-:*:*:*:*:*:*:*
netapp hci_compute_node — cpe:2.3:h:netapp:hci_compute_node:-:*:*:*:*:*:*:*
netapp hci_storage_node — cpe:2.3:h:netapp:hci_storage_node:-:*:*:*:*:*:*:*
broadcom fabric_operating_system — cpe:2.3:o:broadcom:fabric_operating_system:-:*:*:*:*:*:*:*
netapp aff_a700s_firmware — cpe:2.3:o:netapp:aff_a700s_firmware:-:*:*:*:*:*:*:*
netapp fas8300_firmware — cpe:2.3:o:netapp:fas8300_firmware:-:*:*:*:*:*:*:*
netapp fas8700_firmware — cpe:2.3:o:netapp:fas8700_firmware:-:*:*:*:*:*:*:*
netapp aff_a400_firmware — cpe:2.3:o:netapp:aff_a400_firmware:-:*:*:*:*:*:*:*
netapp h610s_firmware — cpe:2.3:o:netapp:h610s_firmware:-:*:*:*:*:*:*:*

References for CVE-2019-18805

cvelogic Threat Intelligence